Compiled by: Angie Moline, Colorado State University GK-12 Program

Introduction to

Stream Ecology

Water on EarthVolume (km3) % of Total Residence Time

Oceans 1,370,000,000 97.61 37,000 yrs.

Ice Caps 29,000,000 2.08 16,000 yrs.

Groundwater 4,000,000 0.29 300 yrs.

Fresh lakes 125,000 0.009 1-100 yrs.

Saline lakes 104,000 0.008 10-1,000 yrs.

Soil moisture 67,000 0.005 280 days

Water vapor 14,000 0.0009 9 days

Rivers 1,200 0.00009 12-20 days

Hydrologic Cycle

Runoff

Precipitation

Evaporation

GroundwaterOcean

Lakes/Rivers

Streams and Rivers

Invertebrate Functional Feeding Groups

Functional Group Feeding Mechanism Dominant Food Resource

Example

Shredders Chew conditioned plant tissue or gouge vascular plants

Coarse pieces of decomposing (or live) organic matter, such as leaf litter

Pteronarcys

Collectors Filter particles from the water column or gather them from depositional areas

Fine particles of decomposing organic matter, such as bits of leaf litter and algae, bacteria and feces

Hydropsychidae

Grazers Graze rocks and wood surfaces

Periphyton – attached algae and associated microflora

Ameletus

Predators Capture and engulf prey or ingest body fluids

Animal tissue Odonata

Stream Food Webs

Riparianplants

LeafLitter

GrazerPredator

Algae & Leaves

Fish

River Continuum

Concept• Headwaters Streams

– heavily shaded, leaf litter is important

– shredders / collectors are abundant

• Mid-order Streams– less shaded, algae more

important– grazers abundant

• Large Rivers– not shaded, phytoplankton

present– collectors important